Resumen

ALONSO-DIAZ, Miguel Ángel et al. Dinámica poblacional de Haematobia Irritans en bovinos    del Trópico Mexicano. Rev. Cient. (Maracaibo) [online]. 2007, vol.17, n.4, pp.330-334. ISSN 0798-2259.

Population Dinamic of Haematobia irritans on Cattle in the Mexican Tropic. ABSTRACT The population fluctuation of Haematobia irritans was evaluated in this study from February 2004 to February 2005 at Martínez de la Torre, Veracruz, México. Distribution of horn fly throughout a year was monitored in 15 heifers F1 (Holstein x Brahman) of 11±2 months of age and 170±19 kg of weight. In addition, horn fly population was correlated with five weather variables and evaluated by weekly counts with direct observation on grazing cattle. H. irritans was present year round (35.1±35.2 flies/cattle); however, higher infestations of this pest were registered during the months of September and October. Population peak of H. irritans was of 121 flies/cattle. The grade of infestation was mainly associated with accumulated rainfall (r = 0.70, P<0.05); nevertheless, other factors as temperature and relative humidity were also important to determine the incidence and severity of the attack of this ecto-parasite. It may be concluded that in this region, H. irritans control must be carried out at the end of the rainy season and at the beginning of windy winter season.

Palabras clave : Population fluctuation; horn fly; Holstein; Brahman; humid tropic.